PCB etching notes in English
aus Metalab, dem offenen Zentrum für meta-disziplinäre Magier und technisch-kreative Enthusiasten.
(As an English-speaking, non-German-speaking visitor to Metalab I thought I'd add a few notes from my experience making a PCB using Metalab facilities. -- follower)
- You can use Google Translate to get an idea of what the German language PCB creation instructions say.
- You can probably find a number of English language UV etching guides online that you can use alongside the translated Metalab specific instructions. I used one from ladyada which was somewhat appropriate.
- I used Kicad to produce the Gerbers and then used  to create a 600 DPI PNG file. I'm not sure if more recent versions of Kicad produce usable print files or not.
- I used GIMP to lay-up multiple copies of the board to be etched in one file. On the CAD station it's in German language but the pretty icons help.
- I printed on transparency twice. I followed ladyada's advice and printed it mirrored to minimise the possibility for light to enter from the side when exposing.
- The copper board I found was roughly 100mm x 160mm.
- There are white lab coats hanging on the back of the door to the "chemistry lab"--you will look particularly menacing when they are accessorised with black gloves.
- The UV light has two rocker switches on the left hand side. One controls On/Off and the other controls IR/IR+UV. You want the IR+UV option. And on.
- After exposure you should be able to faintly see the track outline in a light yellow colour on the board.
- The etching tank took more than ten minutes to heat.
- Once in the etching tank you should see a colour change (the non-resist area will turn an orangey colour) within a couple of minutes--these are not the colour change you are looking for. Take my word for it. You can confirm this by testing the complete conductivity of the board with a multimeter.
- After multiple stops and starts it took maybe 15-20 minutes to etch the board. Once the copper finally starts to disappear it is quite rapid however. Keep an eye on it and maybe re-orientate the board to ensure even coverage.